Contact-finger for electrical controllers and switches.



R; 0, LYNESS v CONTACT FINGER FOR ELECTRICAL CONTROLLERS AND SWITCHES. APPLICATION FILED JUHE 27, 1910' 977,460. Patented Dec. 6, 1910.

Tigfl WITNESSE O: v I INVENTOR ATTORNEYS 'BOBERT CRAWFORD LYN'mS, 0F SUHDERLAND, ENGLAND.

' CONTACT-FINGER FOR ELECTRICAL CONTROLLERS AND SWITCHES.

Specification of Letters Patent.

Patented Dec. 6, 1910.-

Application filed June 27, 1910. Serial No. 569,157.

Toall whom it may concern:

Be it known that I, ROBERT CRAWFORD LYNESS, citizen of Great Britain, residing at 14 Waterloo Place, Sunderland, in England, have invented new and useful Improvements in Contact-Fingers for Electrical Controllers and Switches, of which the following is a s cification.

he object of my invention is to provide a. contact finger as required for electrical controllers and switches,so that such finger can if desired be easily attached to the contact base of the controller, and furthermore. that the tip of such finger, which may have one or more wings, as hereinafter described, can be easily attached to such finger when owing to wear and tear or other circumstances, such tip requires replacing or reversing.

To attain my object I provide a metallic strip which I call the finger, also a detachable tip for same. The tip end of this finger is formed by folding back the strip in such a way as to provide a recess of a desired shape. This recess is as far as its outer surface is concerned of a similar design to, but slightly larger than, the internal surface of the recess in the finger tip mentioned hereafter, which has to be attached thereto.

The tip, which is shown in Figure 2 of the drawings, may be formed of one projection-or wing,-as shown by dotted line D, or may have two side projections or wings, as shown by dotted line C Fig. 2, and the ,method of attachment is-simply by wessing the parts of the strip forming the shaped recess together, and allowin the tip to slide into thedesired position; f desired, I provide the lips of the tip with one or more grooves, and on the finger I provide suitable projections corresponding with such grooves so that the attachment is made the more secure. At the contact base end, or the end of the finger which has to be attached to the'contact base of the controller, I also fold the metallic strip, forming a recess havin theouter surface to correspond to, but slig tly larger than the inner surface of a recess in the bracket mentioned here after. I

I provide-a bracketwith a recess the inner surface of which corresponds to, but is slightly smaller than, the outer surface of the recess fprmed at the base end of the finger, so that such finger can be attached to such bracket in the same way as the finger is attached to the tip. The bracket is attached by means of screws or other methods to the base of the cont-roller. Similar grooves and projections to those on the tip and tip end of the finger maybe formed on this bracket and. base end oftlie finger respectively.

If it is existing type of controllers, then the me tallic strip is not folded back at the base end, but it is' provided with the existing means of attachment, namely by. screws or other similar methods.

To further illustrate my invention, I furnish the accompanying drawings Fig. 1, represents top or sectional view of a metallic finger having the base end plain for ordinary attachment to controller, A 1s the formed recess to receive the tip shown on Fig. 2, B is an adjusting screw with lock nut, E shows the projections on strip, which correspond to redesses F on Fig. 2.

Fig. 2, shows a top View of the metallic tlp which slides over the recess at the tip end'of Fig. 1 when the wing of the finger strip is compressed. The shape of this tip may be varied as for instance according to the dotted lines C or .D, F shows the small recesses in the metallic tip which correspond with the projections E in Fig. 1.

Fig. 3, shows a front view of metallic finger tip and entrance to recesses therein.

Fig. 4, is a front view of Fig. 1.

Fig. 5, shows a finger having a formed recess at each end, the outer end showing a tip attached thereto, while the inner or base end 11s arringed to fit in to the bracket shown of ig. I

Fig. 6, is a front view of Fig. 5.

Fig. 7,'shows a section of a bracket which is attached to the controller base, and is pro--.

vided with a recess corresponding to the external surface of the recess at the base end of the finger shown on Fig. 5.

Fig. 8, 1s a front view of Fig. 7.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is 1. In combination, a contact finger comprising a metal strip having one of its ends bent back to form a loop and a contact tip having a recess adapted to embrace said loop.

2. In combination,.a contact finger comdesired to attachthe finger to the.

its ends bent back to form a loop rising a resilient metal strip having one of and a contact tip having a recess adapte to embrace said loop, whereby it is retained in position by the resiliency "of the metal forming the loo v In combination, a contact fin er comrising a metal strip having one 0 its ends sent back to form a loop and a contact tip having a recess adapted to embrace said loop, said recess being ofthe same configuration as said loop but being of smaller dimensions, whereby when said tip is in position upon said finger the portions of the stri forming the loop will be pressed inward rom their normal position. 4. In combination, a contact fin er comrising a metal strip having one o its ends gent back to form a loop, said loop being provided with an outwardly extending provits ends bent back to form a loop and 'a contact tip having a recess adapted to embrace said loop, whereby said tip will be retained in position by the resiliency of the metal forming the loop, the other end of said contact finger being bent back to form a resilient 'loopfor attachlng the finger to a support.

In testimony whereof I have signed my name to this specification in the presence of 5 two subscribing witnesses.

ROBERT CRAWFORD LYN ESS. Witnesses:

WILLIAM SIMPSON, WILLIAM JAMES WVHYTE. 

